find force and how high an object is

Question

a. 25 J of work was done on a box to lift it 1.5 m. What force was applied to the box to lift it?

b. A 15 kg rock has 300 J of gravitational potential energy stored in it. How high above the ground is the rock?

Answer 1

well for part A we have the formula F(force) *distance(d) = W (work) then we transform this into F=W/d and we get F= 25J/1.5 metres and we get 16.67 Newtons of force for part b we see that gravitational potential energy is potential energy(PE) =Mass(m) *the acceleration of gravity on earth.(g)*the height from designated as zero(h). Then we get PE/(m*g) =h then h=300/(147) and then we get h = 2.04 metres.